The three-dimensional image display applies stereoscopic or autostereoscopic technique to display three-dimensional images. The stereoscopic technique implements the three-dimensional effect by the image parallax of the viewer's right and left eyes. The stereoscopic technique includes the methods with the polarized glasses and without the polarized glasses, which are widely employed. In the manner of taking polarized glasses, the image parallax of the viewer's right and left eyes can be displayed on the display apparatus based on direct sense of sight by changing the polarization direction of the image parallax of the viewer's right and left eyes. For example, a film-type patterned retarder (FPR) is applied to liquid crystal display (LCD) so that the viewer is capable of viewing the three-dimensional image using the polarized glasses. In the manner without polarized glasses, an optical plate with the separated image parallax of the viewer's right and left eyes in an optical axis is installed before or after the display apparatus for generating three-dimensional image.
Conventionally, when the viewer squarely observes the three-dimensional image on the LCD, the vertical viewing angle is decreased, which results from the image crosstalk. In other words, one eye of the viewer observes the image signal originally projected to the other eye of the viewer so that the image signal of the right eye is interfered with the other image signal of the left eye, which results in a narrowed visual field angle. Consequently, there is a need to develop a stereoscopic image display apparatus to solve the problem of image crosstalk while viewing the LCD in a slant manner.